A number of treatments involving the administration of single drugs are currently recommended for pain relief The single administration of narcotic and non-narcotic analgesics and NSAIDs have been shown to display pain alleviating properties. Some anti-epileptics, such as gabapentin and pregabalin, have also demonstrated pain alleviating properties.
Despite the benefits derived from current single drug pain relief regimens, these regimens have disadvantages. One area of concern relates to the incidence of unwanted side effects caused by many of the pain treatment regimens available today. Narcotic analgesics, such as morphine, are sparingly prescribed for pain because of the well-known addictive effects and significant central nervous system (CNS) side effects and gastrointestinal side effects resulting from their single administration. Another class of drugs often used alone for treatment of pain, non-steroidal anti-inflammatory drugs, such as ibuprofen and naproxen, are criticized for their irritation of the gastrointestinal tract.
Another concern of current pain treatment regimens relates to their effectiveness. Many single active ingredients employed in current pain relief regimens cannot achieve adequate pain alleviation even at their maximum therapeutic approved doses in some severe pain states. In addition to not achieving adequate pain alleviation, increasing the drug dose may produce an increase in unwanted side effects such as cognitive impairment, nausea, and constipation.
In view of these concerns, it is evident that there is a need for an improved pain regimen that provides an improved therapeutic benefit (ie, reduced severity and/or frequency of pain) and/or reduces the incidence of unwanted side effects caused by many of the current regimens.